Brighter is always an option, especially with the more powerful early Tele pickups that had a less bright/more middly sound than later pickups had. And with a bass, it is always a decent option.
But yes, the fixed bass sound wasn't a popular choice. But it was the first days of the electric guitar and they were trying to make it versatile. They didn't know how things were going to develop. band-wise, they were trying to guess. No P-Bass around at the time, so they were expecting guitar players to fill-in as bass players if necessary.